QRhiGles2: replace two QSet<int> with QDuplicateTracker

Apart from a more fitting, minimal, API, QDuplicateTracker also
transparently uses C++17 pmr::monotonic_buffer_resource to avoid,
or at least reduce, memory allocations.

Pick-to: 6.3
Change-Id: Ied2574734949b2dadc1bcbaa9d1e3c0ed98ba50a
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

2 files changed, 9 insertions, 8 deletions

diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index 8d8043b7e0..0c2225f194 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -4354,7 +4354,7 @@ void QRhiGles2::registerUniformIfActive(const QShaderDescription::BlockVariable
                                         int binding,
                                         int baseOffset,
                                         GLuint program,
-                                        QSet<int> *activeUniformLocations,
+                                        QDuplicateTracker<int, 256> *activeUniformLocations,
                                         QGles2UniformDescriptionVector *dst)
 {
     if (var.type == QShaderDescription::Struct) {
@@ -4371,8 +4371,7 @@ void QRhiGles2::registerUniformIfActive(const QShaderDescription::BlockVariable
     // that is not the case, it won't break anything, but we'll generate
     // unnecessary glUniform* calls then.
     uniform.glslLocation = f->glGetUniformLocation(program, name.constData());
-    if (uniform.glslLocation >= 0 && !activeUniformLocations->contains(uniform.glslLocation)) {
-        activeUniformLocations->insert(uniform.glslLocation);
+    if (uniform.glslLocation >= 0 && !activeUniformLocations->hasSeen(uniform.glslLocation)) {
         if (var.arrayDims.count() > 1) {
             qWarning("Array '%s' has more than one dimension. This is not supported.",
                      var.name.constData());
@@ -4388,7 +4387,7 @@ void QRhiGles2::registerUniformIfActive(const QShaderDescription::BlockVariable
 
 void QRhiGles2::gatherUniforms(GLuint program,
                                const QShaderDescription::UniformBlock &ub,
-                               QSet<int> *activeUniformLocations,
+                               QDuplicateTracker<int, 256> *activeUniformLocations,
                                QGles2UniformDescriptionVector *dst)
 {
     QByteArray prefix = ub.structName + '.';
@@ -5517,7 +5516,7 @@ bool QGles2GraphicsPipeline::create()
     // Use the same work area for the vertex & fragment stages, thus ensuring
     // that we will not do superfluous glUniform calls for uniforms that are
     // present in both shaders.
-    QSet<int> activeUniformLocations;
+    QDuplicateTracker<int, 256> activeUniformLocations;
 
     for (const QRhiShaderStage &shaderStage : qAsConst(m_shaderStages)) {
         if (isGraphicsStage(shaderStage)) {
@@ -5628,7 +5627,7 @@ bool QGles2ComputePipeline::create()
         }
     }
 
-    QSet<int> activeUniformLocations;
+    QDuplicateTracker<int, 256> activeUniformLocations;
     for (const QShaderDescription::UniformBlock &ub : csDesc.uniformBlocks())
         rhiD->gatherUniforms(program, ub, &activeUniformLocations, &uniforms);
     for (const QShaderDescription::InOutVariable &v : csDesc.combinedImageSamplers())
diff --git a/src/gui/rhi/qrhigles2_p_p.h b/src/gui/rhi/qrhigles2_p_p.h
index e4bf67ea0d..ade0ec9748 100644
--- a/src/gui/rhi/qrhigles2_p_p.h
+++ b/src/gui/rhi/qrhigles2_p_p.h
@@ -58,6 +58,8 @@
 #include <QByteArray>
 #include <QSurface>
 
+#include <QtCore/private/qduplicatetracker_p.h>
+
 QT_BEGIN_NAMESPACE
 
 class QOpenGLExtensions;
@@ -882,10 +884,10 @@ public:
     void registerUniformIfActive(const QShaderDescription::BlockVariable &var,
                                  const QByteArray &namePrefix, int binding, int baseOffset,
                                  GLuint program,
-                                 QSet<int> *activeUniformLocations,
+                                 QDuplicateTracker<int, 256> *activeUniformLocations,
                                  QGles2UniformDescriptionVector *dst);
     void gatherUniforms(GLuint program, const QShaderDescription::UniformBlock &ub,
-                        QSet<int> *activeUniformLocations, QGles2UniformDescriptionVector *dst);
+                        QDuplicateTracker<int, 256> *activeUniformLocations, QGles2UniformDescriptionVector *dst);
     void gatherSamplers(GLuint program, const QShaderDescription::InOutVariable &v,
                         QGles2SamplerDescriptionVector *dst);
     void gatherGeneratedSamplers(GLuint program,